CN117136486A

CN117136486A - motor

Info

Publication number: CN117136486A
Application number: CN202280028526.3A
Authority: CN
Inventors: 朴昶炫
Original assignee: LG Innotek Co Ltd
Current assignee: LG Innotek Co Ltd
Priority date: 2021-04-13
Filing date: 2022-04-13
Publication date: 2023-11-28
Also published as: JP2024514331A; KR20220141562A; WO2022220586A1

Abstract

The present invention includes a shaft, a rotor coupled to the shaft, and a stator arranged to correspond to the rotor, wherein the rotor includes a rotor core and a magnet coupled to the rotor core, the rotor core includes a hole passing through the rotor core in an axial direction, and the hole has the magnet arranged therein, the rotor core includes an outer circumferential surface having a groove extending in the axial direction, and the groove has a center that does not overlap the hole in a radial direction of the shaft.

Description

Motor

Technical Field

The present invention relates to a motor.

Background

Typically, the rotor rotates due to electromagnetic effects between the rotor and the stator in the motor. In this case, the shaft connected to the rotor is also rotated to generate a rotational driving force.

The rotor may include a rotor core and a magnet disposed on the rotor core. The magnets cause electrical interaction with the coils of the wound stator. To ensure the torque required by the motor, magnets may be provided on the outer surface of the rotor core such that the magnets are provided close to the stator. However, when the magnet is provided on the outer surface of the rotor core, there is a problem in that a separate structure for preventing the magnet from being separated from the rotor core is required.

Disclosure of Invention

Technical problem

Accordingly, the present invention aims to provide a motor having an increased torque without providing a separate structure for preventing separation of magnets.

The objects to be solved by the present invention are not limited to the above objects, and other objects not described above will be clearly understood by those skilled in the art from the following description.

Technical proposal

An aspect of the present invention provides a motor including a shaft, a rotor coupled to the shaft, and a stator provided to correspond to the rotor, wherein the rotor includes a rotor core and a magnet coupled to the rotor core, the rotor core includes a hole passing through the rotor core in an axial direction, and the magnet is provided in the hole, an outer circumferential surface of the rotor core includes a groove extending in the axial direction, and a center of the groove does not overlap the hole in a radial direction of the shaft.

Another aspect of the present invention provides a motor including a shaft, a rotor coupled to the shaft, and a stator disposed to correspond to the rotor, wherein the rotor includes a rotor core and a magnet coupled to the rotor core, the rotor core includes a first hole and a second hole, the magnet is disposed in the first hole and the second hole, an outer circumferential surface of the rotor core includes a groove extending in an axial direction, and the groove is disposed between the first hole and the second hole in a circumferential direction.

A further aspect of the present invention provides a motor including a shaft, a rotor coupled to the shaft, and a stator provided to correspond to the rotor, wherein the rotor includes a rotor core and a magnet coupled to the rotor core, the rotor core includes a hole passing through the rotor core in an axial direction, and the magnet is provided in the hole, the hole includes a first curved surface, an outer circumferential surface of the rotor core includes a second curved surface formed between two virtual straight lines extending from a center of the rotor core to pass through both ends of the first curved surface of the hole, and the first curved surface and the second curved surface are concentric.

Advantageous effects

According to the embodiment, there is an advantage in that the magnet is provided in the rotor core, and the performance of the motor is also improved.

According to the embodiment, there is an advantage in that a separate structure for preventing separation of the magnets is not required.

According to the embodiment, there is an advantage in that leakage of magnetic flux is prevented due to the grooves provided in the outer surface of the rotor core and between the magnets.

Drawings

Fig. 1 is a side cross-sectional view of a motor according to an embodiment.

Fig. 2 is a plan view of a stator and a rotor.

Fig. 3 is a plan view of the rotor core illustrating the grooves and second curved surfaces of the rotor core and the first curved surface of the bore.

Fig. 4 is an enlarged view of the rotor core, which is an enlarged view illustrating a portion around the hole shown in fig. 3.

Fig. 5 is an enlarged view of the rotor core, illustrating the depth of the grooves.

Fig. 6 is a view of a rotor core of a motor according to another embodiment.

Fig. 7 is an enlarged view of the rotor core, illustrating a portion around the hole.

Detailed Description

The direction parallel to the longitudinal direction (vertical direction) of the shaft is referred to as an axial direction, the direction perpendicular to the axial direction of the shaft is referred to as a radial direction, and the direction along a circle having a radius in the radial direction around the shaft is referred to as a circumferential direction.

Fig. 1 is a side cross-sectional view illustrating a motor according to an embodiment.

Referring to fig. 1, a motor according to an embodiment may include a shaft 100, a rotor 200, a stator 300, a bus bar 400, a bus bar holder 500, and a housing 600.

Hereinafter, the term "inward" is a direction from the housing 600 toward the shaft 100 as the center of the motor, and the term "outward" is a direction opposite to the "inward", i.e., a direction from the shaft 100 toward the housing 600.

Shaft 100 may be coupled to rotor 200. When electromagnetic interaction occurs between the rotor 200 and the stator 300 by supplying current, the rotor 200 rotates, and the shaft 100 rotates with the rotation of the rotor 200.

The rotor 200 rotates due to electrical interaction with the stator 300. The rotor 200 may be disposed to correspond to the stator 300 and disposed inside the stator 300. The rotor 200 may include a rotor core 210 and a magnet 220 disposed on the rotor core 210.

The stator 300 is disposed outside the rotor 200. The stator 300 may include a stator core 310, an insulator 320, and a coil 330. An insulator 320 is seated on the stator core 310. The coil 330 is mounted on the insulator 320. The coil 330 causes electrical interaction with the magnet 220 of the rotor 200.

The bus bar 400 may be disposed on the stator 300. The bus bar 400 is electrically connected to the coil 330. In addition, the bus bar 400 may be connected to an external power source.

The bus bar holder 500 supports the bus bar 400. The bus bar holder 500 may be an annular member including the bus bar 400 therein.

The case 600 may be disposed outside the stator 300. The housing 600 may be a cylindrical member having one open side.

Fig. 2 is a plan view illustrating the stator 300 and the rotor 200.

Referring to fig. 2, it is advantageous to arrange the magnets 220 to be closer to the stator 300 in the radial direction under the condition that the magnets 220 have the same size to ensure the performance of the motor. When the magnet 220 is inserted into the hole H of the rotor core 210, the magnet 220 may move away from the stator 300. The motor according to the present embodiment ensures the performance of the motor by arranging the magnet 220 to be maximally close to the stator 300 while inserting the magnet 220 into the hole H of the rotor core 210.

The rotor core 210 includes a hole H. The hole H may be provided through the rotor core 210 in the axial direction. The magnet 220 is inserted into the hole H. The plurality of holes H may be arranged in the circumferential direction of the rotor core 210. Each of the holes H may have a bread shape corresponding to the shape of each of the magnets 220 in the axial direction. When the magnet 220 is formed such that the outer side portion of the magnet 220 in the radial direction has a curved surface, the magnet may be disposed closer to the stator 300 while being accommodated in the hole H.

The magnet 220 may be formed in a bread shape such that an outer side portion has a curved surface and an inner side portion has a flat surface in a radial direction.

Fig. 3 is a plan view of the rotor core 210 illustrating the grooves and the second curved surfaces of the rotor core 210 and the first curved surface of the hole H, and fig. 4 is an enlarged view of the rotor core 210 illustrating an enlarged view of a portion around the hole H shown in fig. 3.

Referring to fig. 3 and 4, the rotor core 210 may include a groove G. The grooves G are provided to extend in the axial direction from the outer surface of the rotor core 210. Each of the grooves G may be disposed between the holes H. The holes H are provided between the magnets 220 adjacent in the circumferential direction to prevent the magnetic flux from not flowing to the stator 300 and from leaking to the adjacent magnets 220.

The groove G may be provided as a plurality of grooves G. All the gaps R between the plurality of grooves G may be the same in the circumferential direction.

The hole H may include a first curved surface CS1. Each of the first curved surfaces CS1 is one of the inner surfaces of the hole H, and is a surface provided at an outer side portion in the radial direction. The first curved surface CS1 allows the magnet 220 to be disposed as close to the stator 300 as possible.

The rotor core 210 may include a plurality of second curved surfaces CS2. Each of the second curved surfaces CS2 is a portion of the outer circumferential surface of the rotor core 210. The plurality of second curved surfaces CS2 may be disposed at equal intervals in the circumferential direction. Each of the grooves G is provided between each adjacent second curved surface CS2.

The second curved surface CS2 may be formed between two virtual straight lines M. In this case, two virtual straight lines M are defined as straight lines extending from the center C of the rotor core 210 to pass through both end portions of the first curved surface CS1 of the hole H. The grooves G are positioned outside the two virtual straight lines M. The center of curvature of the first curved surface CS1 and the center of curvature of the second curved surface CS2 may be the same. The center of curvature of the first curved surface CS1 and the center of curvature of the second curved surface CS2 may be different from the center C of the rotor core 210.

The first curved surface CS1 and the second curved surface CS2 may be provided as a plurality of first curved surfaces CS1 and a plurality of second curved surfaces CS2, and the center of a circle formed by the plurality of first curved surfaces CS1 and the center of a circle formed by the plurality of second curved surfaces CS2 may be the same.

Because the first curved surface CS1 and the second curved surface CS2 are concentric, the distance between the first curved surface CS1 and the second curved surface CS2 in the radial direction is constant around the concentric center. In the radial direction, a corresponding region of the rotor core 210 positioned between the first curved surface CS1 and the second curved surface CS2 restricts the separation of the magnet 220 from the rotor core 210. Accordingly, there is an advantage in that a separate member for fixing the magnet 220 to the rotor core 210 can be omitted. Further, since the thickness of the corresponding region of the rotor core 210 positioned between the first curved surface CS1 and the second curved surface CS2 in the radial direction is small, the loss of magnetic force applied to the stator 300 can be reduced to ensure the performance of the motor.

Meanwhile, the shortest distance L1 from the center of the rotor core 210 to the hole H may be smaller than the shortest distance L2 from the center of the rotor core 210 to the groove G.

Referring to fig. 5, the groove G is disposed such that a center P of the groove G does not overlap with the hole H in the radial direction of the shaft 100. Further, the depth t of the groove G in the radial direction may be in the range of 5% to 6% of the maximum radius of the rotor core 210.

The maximum radius of the rotor core 210 may be a distance from the center of the rotor core 210 to the center of the width of the second curved surface CS2 in the circumferential direction. For example, when the maximum radius of the rotor core 210 is 22.3mm, the depth t of the groove G may be 1.2mm.

When the depth t of the groove G is less than 5% of the maximum radius of the rotor core 210, there is a risk that the magnetic flux may not flow to the stator 300 and may flow to the adjacent magnet 220 and leak. On the other hand, when the depth t of the groove G is greater than 6% of the maximum radius of the rotor core 210, the strength of the hole H cannot be ensured, and thus there is a risk of the hole breaking.

The hole H may include a first hole H and a second hole H, with the groove G interposed therebetween in the circumferential direction. The first groove G and the second groove G are disposed adjacent to each other in the circumferential direction.

Meanwhile, the hole H may include a flat surface PS. The flat surface PS is provided to face the first curved surface CS1 in the radial direction.

Fig. 6 is a view of a rotor core 210 of a motor according to another embodiment, and fig. 7 is an enlarged view of the rotor core 210, which illustrates a portion around a hole H.

Referring to fig. 6 and 7, a rotor core 210 of a motor according to another embodiment may include a first curved surface CS1, a second curved surface CS2, and a third curved surface CS3. The first curved surface CS1 corresponds to the outer surface of the rotor core 210, and the second curved surface CS2 is the inner surface of the hole H and is a surface provided at the outer side portion in the radial direction. The third curved surface CS3 is an inner surface of the hole H, and is a surface provided to face the first curved surface CS1 in the radial direction. The center of the circle formed by the third curved surface CS3 may be different from the center of the circle formed by the first curved surface CS1. And the radius of curvature of the third curved surface CS3 may be greater than the radius of curvature of the first curved surface CS1.

The inner surface of the magnet 220 inserted into the hole H to correspond to the third curved surface CS3 may be formed as a curved surface.

The above-described embodiments may be used in various devices such as a vehicle or a home appliance.

Claims

1. A motor, comprising:

a shaft;

a rotor coupled to the shaft; and

a stator provided in correspondence with the rotor,

wherein the rotor comprises a rotor core and a magnet coupled to the rotor core,

the rotor core includes a hole passing through the rotor core in an axial direction, and the magnet is disposed in the hole,

the outer circumferential surface of the rotor core includes a groove extending in the axial direction, and

the center of the groove does not overlap the hole in the radial direction of the shaft.

2. A motor, comprising:

a shaft;

a rotor coupled to the shaft; and

a stator provided in correspondence with the rotor,

the rotor core includes a first hole and a second hole, the magnet is disposed in the first hole and the second hole,

the groove is disposed between the first hole and the second hole in a circumferential direction.

3. A motor, comprising:

a shaft;

a rotor coupled to the shaft; and

a stator provided in correspondence with the rotor,

the aperture comprises a first curved surface and,

the outer circumferential surface of the rotor core includes a second curved surface formed between two virtual straight lines extending from the center of the rotor core through both ends of the first curved surface of the hole, and

the first curved surface and the second curved surface are concentric.

4. The motor according to claim 1 or 2, wherein a depth of each of the grooves in a radial direction is 5% to 6% of a maximum radius of the rotor core.

5. The motor according to claim 1 or 2, wherein a shortest distance from a center of the rotor core to each of the holes is smaller than a shortest distance from the center to each of the grooves.

6. The motor of claim 1, wherein the number of grooves is equal to the number of holes.

7. The motor of claim 1, wherein a distance in a circumferential direction between the plurality of grooves is the same.

8. A motor as claimed in claim 3, wherein:

the first curved surface and the second curved surface are provided as a plurality of first curved surfaces and a plurality of second curved surfaces; and is also provided with

The center of the circle formed by the plurality of first curved surfaces is the same as the center of the circle formed by the plurality of second curved surfaces.

9. A motor according to claim 3, wherein the hole includes a first flat surface disposed to face the first curved surface in a radial direction.

10. A motor as claimed in claim 3, wherein:

the hole includes a third curved surface disposed to face the first curved surface in a radial direction; and is also provided with

The center of the circle formed by the third curved surface is different from the center of the circle formed by the first curved surface.